chrome/browser/ui/gtk/menu_bar_helper.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4 //
   5 // This class replicates some menubar behaviors that are tricky to get right.
   6 // It is used to create a more native feel for the bookmark bar.
   7
   8 #ifndef CHROME_BROWSER_UI_GTK_MENU_BAR_HELPER_H_
   9 #define CHROME_BROWSER_UI_GTK_MENU_BAR_HELPER_H_
  10
  11 #include <gtk/gtk.h>
  12
  13 #include <vector>
  14
  15 #include "base/memory/scoped_ptr.h"
  16 #include "ui/base/gtk/gtk_signal.h"
  17
  18 namespace ui {
  19 class GtkSignalRegistrar;
  20 }
  21
  22 class MenuBarHelper {
  23  public:
  24   class Delegate {
  25    public:
  26     virtual ~Delegate() {}
  27
  28     // Called when a the menu for a button ought to be triggered.
  29     virtual void PopupForButton(GtkWidget* button) = 0;
  30     virtual void PopupForButtonNextTo(GtkWidget* button,
  31                                       GtkMenuDirectionType dir) = 0;
  32   };
  33
  34   // |delegate| cannot be null.
  35   explicit MenuBarHelper(Delegate* delegate);
  36   ~MenuBarHelper();
  37
  38   // Must be called whenever a button's menu starts showing. It triggers the
  39   // MenuBarHelper to start listening for certain events.
  40   void MenuStartedShowing(GtkWidget* button, GtkWidget* menu);
  41
  42   // Add |button| to the set of buttons we care about.
  43   void Add(GtkWidget* button);
  44
  45   // Remove |button| from the set of buttons we care about.
  46   void Remove(GtkWidget* button);
  47
  48   // Clear all buttons from the set.
  49   void Clear();
  50
  51  private:
  52   CHROMEGTK_CALLBACK_0(MenuBarHelper, void, OnMenuHiddenOrDestroyed);
  53   CHROMEGTK_CALLBACK_1(MenuBarHelper, gboolean, OnMenuMotionNotify,
  54                        GdkEventMotion*);
  55   CHROMEGTK_CALLBACK_1(MenuBarHelper, void, OnMenuMoveCurrent,
  56                        GtkMenuDirectionType);
  57
  58   // The buttons for which we pop up menus. We do not own these, or even add
  59   // refs to them.
  60   std::vector<GtkWidget*> buttons_;
  61
  62   // The button that is currently showing a menu, or NULL.
  63   GtkWidget* button_showing_menu_;
  64
  65   // The highest level menu that is currently showing, or NULL.
  66   GtkWidget* showing_menu_;
  67
  68   // All the submenus of |showing_menu_|. We connect to motion events on all
  69   // of them.
  70   std::vector<GtkWidget*> submenus_;
  71
  72   // Signal handlers that are attached only between the "show" and "hide" events
  73   // for the menu.
  74   scoped_ptr<ui::GtkSignalRegistrar> signal_handlers_;
  75
  76   Delegate* delegate_;
  77 };
  78
  79 #endif  // CHROME_BROWSER_UI_GTK_MENU_BAR_HELPER_H_